This application is a division of application Ser. No. 09/313,347, filed May 18, 1999, now U.S. Pat. No. 6,398,890.
This application claims the priority of German patent document No. 198 22 425.7, filed May 19, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a trim part for decorative purposes, especially for the interior trim of passenger compartments of vehicles, as well as to a method for manufacturing such a trim part.
The use of natural materials such as wood, wood veneer, leather, textiles and the like for decorating interiors is generally known, especially also for the interior trim of passenger compartments of vehicles. During manufacture, the natural material is frequently applied as a cover layer to the visible side of a base part that faces the observer.
The disadvantage of using these materials is a limited freedom of design, since only a limited number of patterns and color variations are available. This is especially true of materials that are generally associated with the concepts of exclusivity and luxury, such as burl walnut for example.
The object of the invention is to provide a trim part having a decorative cover layer for which there are many different design possibilities and which also lends the interior of the vehicle an exclusive character, with no increase in cost or manufacturing technology compared with the previously conventional possibilities.
This and other objects and advantages are achieved by the trim part according to the invention, in which a cover layer of natural stone is applied to the visible side of a base part. The trim part is manufactured by machining a negative shape of the base part from a block of natural stone and joining the machined stone to the base part to form a sandwich. The exposed stone surface is then machined and lacquered.
An advantageous novel decorative effect is achieved by using a cover layer made of natural stone. Because of the rich variety of kinds of stone, of which approximately 6000 would be basically suitable for the purpose, there are many variations in pattern and color. A few types of stones even have luminescence effects, thus permitting considerable freedom of design.
Another advantage is that, depending on the type of stone, only a limited cost of raw materials can be incurred since even debris from construction activity may be used.
The freedom from rot and corrosion of the cover layer made of natural stone is also advantageous, so that it can be used not only in the interior area but also in the exterior area.
Natural stone as such offers the designer several very attractive properties. With material inclusions, such as feldspars for example, noble metals, or organic matter, a unique depth effect is produced that cannot be achieved by the use of synthetic materials.
Moreover, stone, especially the types that contain lime, exhibits very impressive optical properties. Thus for example, in a few types of marble with organic inclusions, light is emitted again on a different wavelength, staggered in time. The stone, which is actually white, glows in green veins after the light is shut off.
Another example is a fine-grained gray granite known as Blue Eyes, which glows with an intense blue light depending on the way it is struck by light. In order to utilize optimally the depth effect and the optimum effects of the natural stone, the use of monolithic natural stone blocks for making trim parts and trim strips according to the method of the invention is especially attractive.
Due to the efficiency with which the natural stone can be worked, the manufacturing method according to the invention does not result in any price disadvantage relative to wood. In fact, the eventual costs can even be reduced, with the price of the starting material being more favorable on the average.
Connecting the natural stone with the base part before final machining has the advantage that impacts or bending moments during handling, machining of the visible side of the cover layer, or assembly of the natural stone, the stone is not prone to destruction as would be a thin layer of natural stone by itself. The base part acts as a sort of protection or reinforcement for the natural stone.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.